/*
 * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.variable;

import jakarta.persistence.EntityManager;
import java.lang.reflect.InvocationTargetException;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import org.activiti.engine.ActivitiException;
import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.impl.context.Context;
import org.activiti.engine.impl.util.ReflectUtil;

/**

 */
public class JPAEntityMappings {

    private Map<String, EntityMetaData> classMetaDatamap;

    private JPAEntityScanner enitityScanner;

    public JPAEntityMappings() {
        classMetaDatamap = new HashMap<String, EntityMetaData>();
        enitityScanner = new JPAEntityScanner();
    }

    public boolean isJPAEntity(Object value) {
        if (value != null) {
            // EntityMetaData will be added for all classes, even those who are
            // not
            // JPA-entities to prevent unneeded annotation scanning
            return getEntityMetaData(value.getClass()).isJPAEntity();
        }
        return false;
    }

    public EntityMetaData getEntityMetaData(Class<?> clazz) {
        EntityMetaData metaData = classMetaDatamap.get(clazz.getName());
        if (metaData == null) {
            // Class not present in meta-data map, create metaData for it and
            // add
            metaData = scanClass(clazz);
            classMetaDatamap.put(clazz.getName(), metaData);
        }
        return metaData;
    }

    private EntityMetaData scanClass(Class<?> clazz) {
        return enitityScanner.scanClass(clazz);
    }

    public String getJPAClassString(Object value) {
        if (value == null) {
            throw new ActivitiIllegalArgumentException("null value cannot be saved");
        }

        EntityMetaData metaData = getEntityMetaData(value.getClass());
        if (!metaData.isJPAEntity()) {
            throw new ActivitiIllegalArgumentException(
                "Object is not a JPA Entity: class='" + value.getClass() + "', " + value
            );
        }

        // Extract the class from the Entity instance
        return metaData.getEntityClass().getName();
    }

    public String getJPAIdString(Object value) {
        EntityMetaData metaData = getEntityMetaData(value.getClass());
        if (!metaData.isJPAEntity()) {
            throw new ActivitiIllegalArgumentException(
                "Object is not a JPA Entity: class='" + value.getClass() + "', " + value
            );
        }
        Object idValue = getIdValue(value, metaData);
        return getIdString(idValue);
    }

    public Object getIdValue(Object value, EntityMetaData metaData) {
        try {
            if (metaData.getIdMethod() != null) {
                return metaData.getIdMethod().invoke(value);
            } else if (metaData.getIdField() != null) {
                return metaData.getIdField().get(value);
            }
        } catch (IllegalArgumentException iae) {
            throw new ActivitiException(
                "Illegal argument exception when getting value from id method/field on JPAEntity",
                iae
            );
        } catch (IllegalAccessException iae) {
            throw new ActivitiException("Cannot access id method/field for JPA Entity", iae);
        } catch (InvocationTargetException ite) {
            throw new ActivitiException(
                "Exception occurred while getting value from id field/method on JPAEntity: " +
                ite.getCause().getMessage(),
                ite.getCause()
            );
        }

        // Fall trough when no method and field is set
        throw new ActivitiException("Cannot get id from JPA Entity, no id method/field set");
    }

    public Object getJPAEntity(String className, String idString) {
        Class<?> entityClass = null;
        entityClass = ReflectUtil.loadClass(className);

        EntityMetaData metaData = getEntityMetaData(entityClass);

        // Create primary key of right type
        Object primaryKey = createId(metaData, idString);
        return findEntity(entityClass, primaryKey);
    }

    private Object findEntity(Class<?> entityClass, Object primaryKey) {
        EntityManager em = Context.getCommandContext().getSession(EntityManagerSession.class).getEntityManager();

        Object entity = em.find(entityClass, primaryKey);
        if (entity == null) {
            throw new ActivitiException("Entity does not exist: " + entityClass.getName() + " - " + primaryKey);
        }
        return entity;
    }

    public Object createId(EntityMetaData metaData, String string) {
        Class<?> type = metaData.getIdType();
        // According to JPA-spec all primitive types (and wrappers) are
        // supported, String, util.Date, sql.Date,
        // BigDecimal and BigInteger
        if (type == Long.class || type == long.class) {
            return Long.parseLong(string);
        } else if (type == String.class) {
            return string;
        } else if (type == Byte.class || type == byte.class) {
            return Byte.parseByte(string);
        } else if (type == Short.class || type == short.class) {
            return Short.parseShort(string);
        } else if (type == Integer.class || type == int.class) {
            return Integer.parseInt(string);
        } else if (type == Float.class || type == float.class) {
            return Float.parseFloat(string);
        } else if (type == Double.class || type == double.class) {
            return Double.parseDouble(string);
        } else if (type == Character.class || type == char.class) {
            return Character.valueOf(string.charAt(0));
        } else if (type == java.util.Date.class) {
            return new java.util.Date(Long.parseLong(string));
        } else if (type == java.sql.Date.class) {
            return new java.sql.Date(Long.parseLong(string));
        } else if (type == BigDecimal.class) {
            return new BigDecimal(string);
        } else if (type == BigInteger.class) {
            return new BigInteger(string);
        } else if (type == UUID.class) {
            return UUID.fromString(string);
        } else {
            throw new ActivitiIllegalArgumentException(
                "Unsupported Primary key type for JPA-Entity: " + type.getName()
            );
        }
    }

    public String getIdString(Object value) {
        if (value == null) {
            throw new ActivitiIllegalArgumentException("Value of primary key for JPA-Entity cannot be null");
        }
        // Only java.sql.date and java.util.date require custom handling, the
        // other types
        // can just use toString()
        if (value instanceof java.util.Date) {
            return "" + ((java.util.Date) value).getTime();
        } else if (value instanceof java.sql.Date) {
            return "" + ((java.sql.Date) value).getTime();
        } else if (
            value instanceof Long ||
            value instanceof String ||
            value instanceof Byte ||
            value instanceof Short ||
            value instanceof Integer ||
            value instanceof Float ||
            value instanceof Double ||
            value instanceof Character ||
            value instanceof BigDecimal ||
            value instanceof BigInteger ||
            value instanceof UUID
        ) {
            return value.toString();
        } else {
            throw new ActivitiIllegalArgumentException(
                "Unsupported Primary key type for JPA-Entity: " + value.getClass().getName()
            );
        }
    }
}
